Water Leak Front Motor Mount 60 Vette

[James S.]

This is an original engine 283 Vette. See the excerpt in blue below; another Corvette owner who writes regarding water leakage from the front engine mount as the torque twists the engine. Is this a common problem, and if so is there a solution?

"The problem I face is that the front motor mounting frame spans across the front of the motor between the block and the water pump. The water pump bolts go through the water pump and also hold the engine to the mounting rail. This setup needs one gasket between the motor mount frame and the block and another gasket between the mount frame and the water pump. When the engine is reved, it torques and twists these gaskets loose causing leaks. A possible fix i thought could be securing the motor ridgely to the frame or maybe finding a different motor mounting kit, if there is one. Has anyone ever seen this problem?? Any ideas or comments would be greatly appreciated."

Thanks.

Goatster

[Stuart F.]

Re: Water Leak Front Motor Mount 60 Vette

James;

Maybe I'm alone on this, but I have never before heard of anyone having this problem before. I've worked on a number of c-1's and been associated with many and don't recall anyone else having this problem or reporting on it. That's not to say it doesn't happen, rather if the mount is assembled correctly and the rubber donuts are in reasonably good condition it probably shouldn't. What condition are the rear mounts in? Perhaps one of them is broken causing undue amount of engine movement (torque) on the front mounts.

Stu Fox

[James S.]

Re: Water Leak Front Motor Mount 60 Vette

James;

Maybe I'm alone on this, but I have never before heard of anyone having this problem before. I've worked on a number of c-1's and been associated with many and don't recall anyone else having this problem or reporting on it. That's not to say it doesn't happen, rather if the mount is assembled correctly and the rubber donuts are in reasonably good condition it probably shouldn't. What condition are the rear mounts in? Perhaps one of them is broken causing undue amount of engine movement (torque) on the front mounts.

Stu Fox

Stu,

I'm ready to install a fresh engine and transmission from resto, so all the mounts will are new.

I read that excerpt from another Vette forum. Just wanted to see if anyone else has this problem before I continue installing all the components.

Thx,

Goatster

[Wayne P.]

Re: Water Leak Front Motor Mount 60 Vette

Should not be a problem if you're using new or good parts and gaskets with sealer. Make sure the water pump mount bolts are tight. Not to say it doesn't happen, but in 45 years of playing with C1 Vettes, I've never had this problem. The mount can be bent or badly corroded, if so it should be replaced.

[Scott S.]

Re: Water Leak Front Motor Mount 60 Vette

Good Morning, You must be some lucky bunch of guys. This problem is very common. If you make sure that the surfaces are clean and flat, use gasket sealer/goo the problem should be solved.
You can take two long 3/8 inch bolts and cut the heads off. Then cut a slot in the top of the newly exposed shaft of the bolt. These two bolts can be threaded into the top holes and all of the items can be loaded in place. Then install the lower bolts, take out the upper studs and finish torquing the assembly.
Best of luck.
Scott

[Stuart F.]

Re: Water Leak Front Motor Mount 60 Vette

Scott;

Perhaps this is so. I admit I haven't done much with C-1's of late. Perhaps they are just coming of age now where such corrosion is rearing it's ugly head. Sounds like you've been there done that so your advice should be welcomed.

Stu Fox

[Bernard M.]

Re: Water Leak Front Motor Mount 60 Vette

Be sure to use thread sealant on the bolts. The holes they thread into pass into the water jacket of the block and unless thread sealant is used they will leak.

[Steven B.]

Re: Water Leak Front Motor Mount 60 Vette

I need to reinstall my engine soon and will definately use the above recommendations.

How was it done at St. Louis on the line? Unfortunatley when I disassembled mine I did not pay attention to sealant residue or anything else.

Thanks!

Steve

[John H.]

Re: Water Leak Front Motor Mount 60 Vette

I need to reinstall my engine soon and will definately use the above recommendations.

How was it done at St. Louis on the line? Unfortunatley when I disassembled mine I did not pay attention to sealant residue or anything else.

Thanks!

Steve

Steve -

The upper engine mount bracket was installed at the Flint Engine Plant, not at St. Louis.

As Scott Sinclair noted above, this is a VERY common problem on C1's - I've fixed a lot of them over the years too. Make sure the block surface, both sides of the bracket, and the water pump surfaces are flat and clean with NO pitting, use a film of gasket sealer on both sides of both gaskets on each side, and use the stud trick to "hang" all the elements of the sandwich on so you don't smear the sealer off the surfaces while trying to position everything. Use thread sealer on the water pump bolt threads.

After everything is in place (but before tightening the four bolts), with the engine supported from below, I grab both ends of the upper bracket and push the driver's side down and pull the passenger side up to bottom the bolts out against their holes, then torque the bolts. That prevents the direction of engine torque from causing any shear movement in the "sandwich" of parts.

Have done this many times, never had a leaker afterwards.

[Clem Z.]

Re: Water Leak Front Motor Mount 60 Vette

use the "THINNEST" water pump gasket you can find so they will not compress later and cause a leak. NEVER use the cork ones that come in some engine gasket kits.

[James S.]

Re: Water Leak Front Motor Mount 60 Vette

Thanks for all the comments Gents; really helps alot.

Regarding the front mount bracket on this survivor Vette; the bracket was corroded on both sides, so instead of replacing the original, I brazed both sides; filed down flat, and then sanded smooth, so she looks very nice and restored now.

Thx,

Goatster

[Steven B.]

Re: Water Leak Front Motor Mount 60 Vette

Steve -

The upper engine mount bracket was installed at the Flint Engine Plant, not at St. Louis.

As Scott Sinclair noted above, this is a VERY common problem on C1's - I've fixed a lot of them over the years too. Make sure the block surface, both sides of the bracket, and the water pump surfaces are flat and clean with NO pitting, use a film of gasket sealer on both sides of both gaskets on each side, and use the stud trick to "hang" all the elements of the sandwich on so you don't smear the sealer off the surfaces while trying to position everything. Use thread sealer on the water pump bolt threads.

After everything is in place (but before tightening the four bolts), with the engine supported from below, I grab both ends of the upper bracket and push the driver's side down and pull the passenger side up to bottom the bolts out against their holes, then torque the bolts. That prevents the direction of engine torque from causing any shear movement in the "sandwich" of parts.

Have done this many times, never had a leaker afterwards.

Thanks John and Scott! I will follow those directions. I never thought about moving the support to assure bottom out the bolts!

[David A.]

Re: Water Leak Front Motor Mount 60 Vette

this is a fantastic thread on this topic!!

now, which gasket sealer it the best!!

iowa

[Bruce B.]

Re: Water Leak Front Motor Mount 60 Vette

David,
Permatex #2 will do the trick.
Absolutely NO silicone.

[David A.]

Re: Water Leak Front Motor Mount 60 Vette

permatex # 2 it is
i take it that one does not paint over
the gasket areas of the engine mount bracket
dave